Ambient methane functionalization initiated by electrochemical oxidation of a vanadium (V)-oxo dimer

Abstract

The abundant yet widely distributed methane resources require efficient conversion of methane into liquid chemicals, whereas an ambient selective process with minimal infrastructure support remains to be demonstrated. Here we report selective electrochemical oxidation of CH ₄ to methyl bisulfate (CH ₃OSO ₃H) at ambient pressure and room temperature with a molecular catalyst of vanadium (V)-oxo dimer. This water-tolerant, earth-abundant catalyst possesses a low activation energy (10.8 kcal mol ^‒1) and a high turnover frequency (483 and 1336 hr ⁻¹ at 1-bar and 3-bar pure CH ₄, respectively). The catalytic system electrochemically converts natural gas mixture into liquid products under ambient conditions over 240 h with a Faradaic efficiency of 90% and turnover numbers exceeding 100,000. This tentatively proposed mechanism is applicable to other d ⁰ early transition metal species and represents a new scalable approach that helps mitigate the flaring or direct emission of natural gas at remote locations.

Abstract

The undesirable geological release of methane at remote locations can be lessened through an efficient methane conversion process. Here, the authors report selective ambient functionalization of methane by a vanadium (V)-oxo electrocatalyst with a low activation energy and a high turnover frequency.